Metal-turning tool.



J. HARTNESS.

METAL TURNING TOOL.

APPLICATION FILED SEPT. 9, 1908.

' 1,036,101. Patented Aug.20, 1912.

Z SHEETS-SHEET 1.

J. HARTNESS.

METAL TURNING TOOL.

APPLICATION FILED SEPT. 9, 1908.

1,036,101. Patented .20,1912.

T SHEBT 2.

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Specification of Letters Eatent.

T; J i1 felt-en ten (on Application filed September 9, 1908. serial lilo. 452,368.

To all whom it may concern:

Be it known that l, linens l liin'rnnss, of Springfield, in the county of flindsor' and State of Vermont, have invented certain new and useful Improyenients in Metal-Turning Tools, of which the following is a specification.

This invention has relation to the art of cuttlng metals as practised in metal Working machines, such as engine lathes.

In order that the invention maybe under stood, it is necessary to explain the action ot-thc cutters which have been used in sc-- cordance with the general practice. this kind of work, the cutter is usually carried by a holder which makespossible its adjustment laterally and longitudinally in relation to the work, so that it may be caused to stands at a slight angle to the wall of metal from which the chip is being taken, so that only the extreme edge of this clearance'face (which edge forms the cutting edge) is in contact with the metal. This universal practice of giving a lathe tool a clearance subjects the cutting edge to a onesided pres sure. I This, in turn, necessitates the employinent of very bluntedged tools capable cf withstanding such one'sided pressure. it is obvious that at cutting edge should never be subjected to lateral stress. it cutting edge will stand an enormous strain it the pressure equalized against both faces thereof. lit

is well known that hardened steel may be subjected to an enormous compression stress, but that a thin edge of hardened steel has very little lateral strength But, as stated the universal practice gives a cutting tool a clearance, and then, of course, it is necessary to sacrifice What would otherwise a very desirable feature, to wit a wedge-- shaped cutting edge, measuring say from BO to 45 lu actual practice, it is customary to employ a'tool having s clearsnc anslope of about 15, learing the lip angle of th tool 6& so that the cutting angle, measured from the face of the Work to the top mately that is, the i which should plow oil the c stead of standing at c desirso 30 or 45, stands at an angle 0- 4 action out blunt tools makes the pro turning, a scraping action; in which metal iscrushed and crowded of face of the work.

ln :1 cutting tool, the ideal co be approximated by holding one face c the resultant pressureon its ward in line midway between l have found that the sided pressure upon the cutter stanticlly obviated by perniitti:

2' so-called clearance face "to against; the wall of metal from chip is 'fbeing' removed so that t on the two faces of the cuter may be ore tically equalized.

Having reduced the cutting stress on cutting tool to a compression stress now possible to give the cutting edge the ideal wedgeshape, so that it passes through the metal, Wedging oil its chip instead of scraping or crowding off the nietsl. 'TlIG acute angle removes the chip with the slightest structural change in the meal the chip. Blunt angle tools on the trary produce a chic which j chunks more or less firmly un such cases the thickness or the c erally double the thickness of the the length of the chip spprmat the length of the metal in its original term around the bar.

in order to make it possible to use 2 out ter without. clearance, that is to allow large area of the so-called clearance '3- to contact or beer flatly against the metal from which the chipisbeing the cutter is allowed a slight angular dom so "that it can oscillate for thi only. @therwise the tool held 2 trolled rigidly so that it is under 0 v control of the carriage, so fo r of its cutting edge to the ally snail longitudinull g is coin-six this oscillation must b ter line substantially ccinc o 60 represents the slide formoving the cutter c uttingedge of the tool, so that 'a 'change of Q located I -angular position does. not appreciably change the exact location of the edge. The

amount. of angular motion required is very slight, and abutmen'ts are rovidedto control the, tool within, fixed limits, and means if necessaryare employed to allow the tool" to start intoits cut with a slight clearance, but as soon as the tool has entered its cut,

in orderto putit into its strongest and most durable "position, it maybe swung by hand orothenmeans so that.the-inner face bearsfiatly against the metal of the work; In some work, the-chip throws the'tool into its position automatically, but in all work it tends to hold .the tool therewhe'n it isso For simplicity anangle "of-90, but it will-gbe understood i that thecorner of the tool maybe rounded Y or of any desired shape,and that it is pre-' 1 ferred to; mount the tool vmovably so as to bring thecenterline of oscillation approximately along and in line-with-the top edge I oftheinost acute'part of the tool,v where the thickest portion of the chip isb'eingremovedg, jIt s apparent, however, that, in certain" kinds of work, this center of movement or oscillation may be put" abo've,below, 1 forward or back of the'center: line of this particular part of .theitool; and for acere ta in particular reason hereinafter stated, the line ,of center-ofoscilla'tion mayjnot, pass i along nor .beexactlyparallel with the line ofthe top edge'of the cutterdg Y Upon-the accompanying drawings, there 'isillustrated a' variety of bodying, the invention.

' Figure lprepresents a plan view' 'o one I form: of the inventions Fig. 2' represents I .a:

longitudinal sectiontherethrou'gh. Figs.

and :4-v representend views respectively, showing the cutter in place and being 're moved. .Fig. 5 represents'the cutter. Fig.-

: Gr'epreSentS-a section through another form of-tool embodying the invention.

I Fig.- -7 represents an endelevationthereof. Fig. 8 represents'thecutter as engaged with the work-.;- Fig. 9 shows the end of the cutter. Fi .10 illustrates in side elevation another.

em jodiment of the invention. Fig. 11 represents a plan "viewthereof.-

15 respectively, represent" sections on the lines 1313, 1 4'14,and 1515 of Fig;

10-. Fig. 16 represents a longitudinal section on theline 16-16of Fig. 11. Fig.1?

I about its axisof oscillation. Fig. 1 8 'repre- J sents the end "of said slide; g .1

the "shaft which operates It is knownsi' that thei top slope or outer illustrating the] inven-';

tion, lz-have chosen' to show tools,.-the plan View of the toptedge Of'WhlCll showsi the [two so-called clearance-faces at substantiallyv have found asp .itself isffr i o. swi'n coincident with the; line of the *theoretical different tool limitation; Fig. 12' illustrates the cutter; :Figs' 13, 14 and surface of the tool should be at as acute an angle as possible to the natural travel of the work so as to present the most favorable I surface for lifting of? the chip, yet it has been found in practice that, with a tool havving a clearance, 1t is impossible to ive this slope an angle that will lift the c ip.

It only scrapes itand pushes before it the metal in. chunks -wh1ch are crushed or shearedoff from the work before the tool, and *notactually by the edge thereof. The idealinstrumentality for removing the chip from the work is a wedge. The angle of v the wedge, to secure the best results, should not be over 30. .But, .it has never been practicable to use a wedge on account of the one-sided pressure met with in tools having/a clearance. Consequently, tools have been used which are. not wedges'and hence i the duty has devolved upon ,thefltool of crushing-and. changingethe' shape of the metal, severing or partly severingit into small chunks and;.cleaving or .shearin oil thechunks at an angle to the surface finished by the tooli. '1, l; 1-

reviously indicated, that I may form the cutter withtwo faces atan angle of substantially 30",, and that in actual practice the inner faceofthe tool maybe caused to bear flatly against-the face of the work'by swiveling the toot-and permitting itto have anioscillatorymovementg The tool is preferably so mounted that the'theo retical cutting edge .is under the, absolute coiitrol ,of,=the carriagel although the' cutter about a ce'nter line ferringtothe useof the =tool in "an engine :lathe, the description of the tool used in any other positiongwill be understood from its 'description r'ilijeonneetionlwith a lathe; and

that thephraseolo y. which is employed is for-the purpose. 9 g description and not of Referring to inclusive; I have illustrated a simple embodiment of the invention in whichthe cutter is indicated at 20'. It consists of a bar comprising ashank 21 and an operative end 22. Atthe. end 22,

there is an outer face or top slope- 23, which is at an acute angle to what may-be termed the inner face 24. "The face Qatcorresponds, in a measure, to whathas heretofore been called the cl arance face At-the end of the portion 27, there is a clearance proximately that of splitting off the chip 1 instead of crowding or scraping it ofl as a I heretofore.

necessary that the. cutting edge 26, formed at I stantially about the 'As previously stated, it is not the intersection of the two faces 23 and 24, should be straight. On the contrary, it may be curved in which mounted that it is capable of oscillation subdent with its cutting edge. that the holder, which is indicated at- 27 consists of a flat bar or plate, having along i. one side two'parallel flanges 28, 29, which form a laterally open socket to receive the.

shank of the cutter. The flange 29.-projects beyond the inner end of the holder so as to underlie the operative end of the cutter to support it. The upper wall ofthe flange 29 is concave, asindicated at 30, in crosssection the are "or curvature being concentricwith-the. cutting edge 26 of the cutter, said edge 26 itself being coincident with the corner '31 of the guideway 28. is recessed in its under face 'as at 32, and it is provided with a downwardly projecting lip or edge 33-which forms approximately a right angle to its in- This refntrant corner is in a line concentric with the concave face. 30, and it serves as a fulcrum or pivot in which thecorner 31 of the shank of the cutter is placed and about which the cutter may be 3 oscillated. The corner 31flof the shank is l its fulcrum by adjusting. passed into the side of the holder curved rib 36 on the other; upper I corner of the shank; 21. 1 These screws serve to hold the upper edge orcor- Q 1 -;acute angle,

mately 30?.- stantially a continuation of the corner 56 ner face 34.

held against screws 35 and engaging a ner 31 against the lip 33.

that the cutter is socketed in the holder so that it is capable of oscillation to a limited 1 cutter from leaving extent, To prevent the its guideway, a'removable stop locking de vice is employed consisting ofa rotatable headed pin 37 inserted in the socket in the I fiange29, the head being cut away,- so that, by rotating the pin to the proper point, the cutter. may be laterally removed past the cut-away portion of the head. Passing upwardly through the projecting end of the flange29, there is a pin 38, theend of which is concave, .as shown in Fig. .4, said pin fitting'th'e convex under side 39 of the cut-- ter and holding the cutter upwardly with I lip event the face 24 will be convex. The cutter is here shown as so I,

' which bears upon the top slope 23 center of axis coinci- 1 It "W111 be seenshank 21. The flange or right provided an adjusting screw 40 which is passed transversely through a cylindrical head 41 of a bolt 42. The screw 40 has a head 43 which may be engaged with a socket 44 formed in the outer end of the shank of the cutter. The tool holder is illustrated as being mounted in the conventional tool-post 45 of the lathe slide 46.

It will be apparent that, when the cutter holder is fed along the work (shown in dotted lines in Figs. 1 and 2), the face'24 will tend automatically to position itself with reference to the face or shoulder of the work so as to lie flatly thereagainst, the chip maintaining the cutter in this position. Thus the wedge (the cutter) is presented in such relation to the work that the chip and the face of the work bear with a substantial equality of pressure against both faces of the wedge (or cutter) in other words, one face of the wedge-shaped cutter is placed flatly against the face of the work so that the chip is wedged off by the other face of the cutter which is at awedging angle to the face-or wall of the work. *The inner face of the laterally open socket and the pin 37 serve as stops to limit the lateral oscillation of thecutter. y

In Figs. 6 to 9 inclusive, there is illustrated a tool which may re employed with another. form of engine lathe in which the cutter is supported directly in the lathe slide. ,The holder consists of a cylindrical block 46, provided at its inner end with an oblong aperture, the walls of which are rectangular. The other end of the holder is internally threaded to receive an adjusting 'screw'47, having on its inner end a head 48 of the shank of the tool. The top side 57 of the shank is at an angle less than 90 to its side 58 which is in a plane with its face 55. Its-other side 59 is at substantially a angle to the top side 57, but is at'an obtuse angleto its under side 60, which lat-. ter is at an angle less than 90 to its side 58. In cross-section the shank of the cutter is in the shape of a trapezium with its longest side upright. The height of the side wall 58 is substantially equal. to the height of thesocket in the holder 46, so that the corner 56 of the cutter shank is socketed in the angle formed by the side and top walls of the a erture. By reason of this construction, it will be seen that the cutter is capable of oscillating about the corner 56 and cuts lit: oil from the work and which the top slope 54: of the cutter. Y

engages In both of. these embodimentsof the' iIi- .vention,.- thus described, the cutterfitself is capable of-oscillation about a center coinci dent'with its cutting edge, is oscillation beingrelatively to its holder.: a

' In Figs. to 18 inclusive, there is illustrated a tool in which a device is provided foradjusting or oscillating the cutter'about its center of movement, and also a positive adjustable abutment for limiting the move .ment of the so-called clearance face ofthe tool 'away.'from the wall of metal from .which thechip is being removed. The'cutter 76 hassubstantially the same shape as that shown in Fig. 5. Its corner 77, which is in line with its cutting edge 7 8,.is located in a reentrant angle in a plate. 7 9 which isattached to the, holder 80 by any well known means. The holder e. the bodyand the top plate 79, forms a laterally open socket' for the lateral insertion of the cutter, said plate alsoclamping the under curved side of the cutter in its seat in the holder. The rib 81. on the cutter bears against a surface on the holder, as shown in-Fig. 15. For the purpose of adjusting or oscillating the, outter about its center of oscillation, I employ a slide 82 located in asocket in the holder and having shoulders 83,'8& which embrace, the

thickest portion of thecutter, as shown in Fig. 14;. This sllde may be reciprocated by a cam or eccentric ,85'formed on the end of a rock shaft 86, which has a handle 87 by which it may be rocked. To resist the tendency of the cutter-to swin outward away from the face of the work, there is employed an. adjustable, abutment 88 which may preferably consist of a screw passed into a threaded aperture in the holder and having its edge bearing against the thickest portion of thecutter, as shown in Fig. 13.-

l I do not herein claim the method or art I 'Of'cutting metal which is herein disclosed,

since the same forms the sub'ect matter of my application Serial No. 410 86, filed Jannary-14, 1908. Nor do I herein claim broadly a metal cutting tool having faces at an acute angle to each other terminating in a cutting edge and swiveled with reference to the work so that one of said-faces rests flatly againstthe face ofthe work, as the same forms the subject-matter of my ap lication Serial No. 406,588 filed Dec. 16, 190

Having thus explained the nature of my said invention, and described a way of constructing and using the same, although without attempting to set forth all of the forms in which it may be made or all of the modes of its use, what I claim is:

. edge.

carrier, a cutter havinga substantially wedge-shape cutting end, and means on said carrier for moving said cutter about an axis substantially coincident with its cutting 2. In a shank having at its end two faces at an acute angle to-each other, terminating in a cutting edge longitudinal of said shank, said f cutter being movable on said holder about an axis substantially coincident with said cutting edge.

-3. In.a metalturning tool, a cutter comprising a bar or shank having a cutting edge substantially coincident with one corner thereof, and formed by two faces at an acute angle to each other, and a holder, or carrier having means to receive said corner and to permit said cutterto rock-about said I metal-turning tool, a holder or carrier, and a cutter comprising a bar or 1. In a metal-turning tool, a holder or v 4.]In a metal-turning tool, a cutter come prising a bar or shank having a cutting edge substantially coincident with one corner thereof and formed by two faces at an acute angle to each other, a holder or carrier having means to receive said corner and to perand adjustable means on said holder for supporting the under side of said cutter.

' 5. In a metal. turning tool, a 'cutter, comprising a, bar or shank having on itsupper side a cutting edge extending endwise thereof, and acurvedundeir side or face, and a holder or carrier having a complemental curved seat vto receive said curved side orface, and on which said under side or face of the cutter is adapted laterally to slide, and

means for limiting the lateral sliding movement. of said cutter.

6. In a metal-turning tool, a cutter comprising a bar or shank having acutting edge substantially coincident with one corner thereof and formed by two faces at an acute angle to each other, said bar or shank having .mit said cutter to rockabout said corner,

a curved underside or face, and a holder or carrier having a fulcrum to receive said corner, and having concave surfaces to'fit said curved under side or face of said bar or under side or face being substantially concentric'with'the said fulcrum.

7. In a metal-turning tool, a holder or carrier, a cutter comprising a bar or shank having at its end two faces at an acute angle to each other, terminating in a cutting edge longitudinal of said shank, said cutter being movable on said holder about an axis subshank, said concave surfaces and said curved ner thereof and formed by two faces at an ner thereof, and formed by two faces at an acute angle to each other,,a holder or carrier having means to receive said corner and to permit said'cutter to rock about said corner, and means on said holder or carrier for positively resisting the end thrust of said acute angle to each other, a-holder or carrier having means to receive said corner and to permit said cutter to rock about said corner, and adjustable means on said holder or carrier for adjusting said cutter longitu-' dinally of its cutting edge and said rocking movement.

10. In a metal-turning tool, a cutter comprising a bar or shank having a cutting permitting edge substantially coincident with one crner thereof and formed by two faces at an acute angle to each other, a holder or carrier having means to receive said corner and to permit said cutter to rock about said corner, and movable means for engaging said bar or shank and holding its corner in the said fulcrum.

11. In a metal-turning tool, a cutter comprising a bar or shank having a longitudinal cutting edge formed by faces at an angle less than a right angle, and a holder having in one side a socket to receive said cutter and to permit it to oscillate while in operation;

12. In a.metal-turning tool, an elongated holder having in one face a socketto receive the cutter, and an overhanging lip; and a cutter consisting of a shank or bar havinga longitudinal cutting edge and a portion to engage said lip, and stops on said holder between which said cutter is located,the said stops being separated a distance greater than the width of said cutter to permit an oscillation of said cutter.

- 13, In a metal-turning tool, a' cutter havinga longitudinal cuttin edge, a holder therefor which permits a ree oscillation ofsaid cutter 'on an axis lengthwise of said cutting edge, and manually operated means for oscillating said cutter about said axis to cause its edge 'to bite into the work.

14. In a metal-turning tool, a cutter comprising a bar or shank having side faces at its end which form'a longitudinal cutting edge, and a holder having a supporting surface on which the under face of said bar or shank rests and on which it may move transversely, said holder having a cap plate with a lip or projection for engaging the bar or shank.

15. In a metal-turning tool, a cutter consisting of a bar or shank having at one end a longitudinal cutting edge and having on its outer face a longitudinal rib, and a holder having a surface on which the under side of the bar or shank rests, a portion to engage the inner face of the bar or shank, and a member to engage the rib on said outter', said engaging portion and said member being adjustable one relatively to the other, transversely of the said cutter.

16. Ina metal-turning tool, a cutter consisting of abar or shank having at one end a longitudinal cutting edge and having on its outer face a longitudinal rib, and a holder having a surface on which the under side of the bar or shank rests,aportion to engagejthe inner. face ofthe bar for shank,

and a member'to engage the rib on said outter, said engaging portion and said member being adjustable one relatively to the other, transversely of thesaid cutter,-in combination with means on said holder for oscillating said shank about said engaging portion of the holder as a fulcrum. 7

17. In a metal turning tool, a cutter com-,

prising a bar or shank having-at one end an inner face and a top slope forming an acute angle and terminating in a cutting edge extending lengthwise of said bar or shank, a holder having an opening in one side into which said cutter may be laterally inserted and in which it may move laterally, and means on said holder for engagement with the sides of said cutter to prevent its lateral dislocation.

18.- In a metal turning tool, a cutter comprising a bar or shank having at one end an inner face and a top slope forming an acute angle and terminating in a cutting edge extending lengthwise of said bar or shank, a holder having an opening in one side into which said cutter may be laterally inserted, means on said holder for engagement with the sides of said cutter to prevent its lateral dislocation while permitting it to move laterally, and means engaged with said cutter for adjusting it longitudinally.

19. In a metal turning-tool, a cutter com holder having a socket to receive the cutter and a projection to project downward over the inner side of the bar or shank, and one or more screws for engaging the outer side of said bar or shank and adjustable to permit the cutter to oscillate about aline substantially coincident with its cutting edge.

20. In a metal turning tool, a cutter comprising a bar or shank having at one end an inner face and a top slope forming an acute angle and terminating in a cutting edge extending lengthwise'of said bar or shank, a holder having a socket in one side with a seat in which said cutter is seated to oscillate, said holder having a lip taking downwardly over the inner side of said cutter, one or more screws in said holder for engagement with the outer side of said cutter to hold it against said seat while permitting it to oscillate thereon, and means on said holder in positive engagement with said cutter for holding it against outward endwise movement. I

21. In a metal turning tool, a cutter comprising a bar or shank having at one end an inner face and a top slope forming an acute angle and terminating in a cutting edge extending lengthwise of said bar or shank, said bar or shank having on its outer side near its top a longitudinally extending rib, a holder having a socket in one side with a seat for the cutter, and having a downwardly projecting lip taking over the in-,

ner side of said cutter, and means on said holder bearing against said rib,

In testimony whereof I have aflixed my signature, in presence of two witnesses.

' JAMES 'HARTNESS. Witnesses:

MARCUS B. MAY. I P. W. PEZZETTI. 

